The client is a well-known bentonite deep-processing enterprise located in Northern Greece, specializing in high-performance sodium-based bentonite powder for GCL (Geosynthetic Clay Liner) waterproofing materials. In the second half of 2024, the EU tightened its standards for landfill anti-seepage layers (permeability coefficient ≤ 1×10⁻⁹ cm/s). The client’s existing Raymond mill + mechanical classifier system could only produce D97 15–20 μm powder—no longer sufficient to meet the updated EN standard and the requirements of key customers. To remain competitive, the company needed a breakthrough in bentonite ultrafine grinding, aiming to upgrade product fineness to D97 ≤ 5 μm (over 2500 mesh) in a single pass, while ensuring batch stability and maintaining high yield.
Project Requirements
- Feed material: Bentonite at 325 mesh (<45 μm), moisture < 8%
- Target fineness: D97 ≤ 5 μm, D50 1.8–2.2 μm
- Kapasitet: ≥ 400 kg/h per line
- Additional requirements:
- Ultra-narrow particle size distribution (Span < 1.4)
- Low-temperature grinding to protect the montmorillonite layered structure
- Zero iron contamination (Fe₂O₃ increase < 30 ppm)
- Energy consumption ≤ 110 kWh/t
Equipment Selection: Episk pulver MJW-L800 Air Classifier Mill System for Bentonite Ultrafine Grinding
After on-site trial grinding and comparison tests, the customer selected the Epic Powder MJW-L800 air classifier mill complete system.
Configuration includes:
- Main motor power: 55 kW
- Classifier: High-speed, frequency-controlled turbo classifier (max 2500 rpm)
- Auxiliary equipment: Pulse-jet dust collector, nitrogen closed-loop system (optional), automatic packing line
- Material construction: Core parts made of high-strength wear-resistant ceramics + 316L stainless steel composite structure
Trial & Production Data (Commercial Production Started March 2025)
| Item | Feed Material | Measured Product Data |
|---|---|---|
| Fineness | 325-mesh pass | D97 = 4.68 μm, D50 = 2.01 μm |
| Particle Distribution (Span) | — | 1.32 |
| +5 μm content | — | < 2.1% |
| Actual capacity | — | 430–480 kg/h |
| Specific energy consumption | — | 102–108 kWh/t |
| Iron increase (Fe₂O₃) | — | +18 ppm |
| Swelling index retention | — | 99.1% (almost no structural loss) |
| System yield | — | > 98.5% |
Project Significance
This project represents the first successful large-scale production of bentonite at D97 ≤ 5 μm in the European market using the Epic Powder MJW series air classifier mill. It has become a benchmark case and provides a replicable technical model for upcoming production lines in Greece, Italy, Spain, and other regions.
The customer has already ordered a second MJW-L800 production line and plans to expand total production capacity to 15,000 tons/year of ultrafine sodium bentonite by 2026, entirely for export to the EU high-end waterproofing materials market.